Effect of Smoking on Cepstral Parameters.

Smoking exerts certain damage to the voice, which affects sound characteristics. This study explored the effects of smoking, smoking time, and smoking amount on cepstral parameters. We collected the acoustic signals of sustained vowels in 301 participants (135 smokers and 166 nonsmokers). The cepstral parameters, including cepstral peak prominence (CPP), CPP standard deviation (CPP SD), low to high-frequency spectral ratio (L/H), low to high-frequency spectral ratio standard deviation (L/H SD), and voice disorder cepstral/spectral index of dysphonia (CSID), of the sustained vowels were investigated through the analysis of dysphonia in speech and voice (ADSV) application. The effects of smoking on these parameters were explored. The influences of smoking time and smoking amount on cepstral parameters were also analyzed by multiple linear regression. The CPP and L/H values in the smoking group were lower than those in the nonsmoking group (CPP: P < 0.001, L/H: P = 0.033) and negatively correlated with smoking time (CPP: R = 0.3828, P < 0.0001; L/H: R = 0.02996, P = 0.0447) and smoking amount (CPP: R < 0.4526, P < 0.0001; L/H: R = 0.08823, P = 0.00005). The CPP SD, L/H SD, and CSID values in the smoking group were higher than those in the nonsmoking group (CPP SD: P = 0.006, L/H SD: P = 0.034, CSID: P < 0.001) and positively correlated with smoking time (CPP SD: R = 0.03648, P = 0.0265, L/H SD: R = 0.09121, P = 0.0004, CSID: R = 0.01247, P = 0.1972) and smoking amount (CPP SD: R = 0.05495, P = 0.0062, L/H SD: R = 0.1316, P < 0.0001, CSID: R = 0.03851, P = 0.0225). Compared with other cepstral parameters, smoking time and smoking volume had the greatest impact on CPP (smoking time: R = 0.385, smoking amount: R = 0.443). This study confirmed that smoking has a significant effect on cepstral parameters. Compared with the cepstral parameters of nonsmokers, an increase in smoking time and smoking volume increases the abnormality of the cepstral parameters of smokers.